Fears that a mega-thrust quake like the type that struckJapan on March 11, 2011 are mounting among leadingAmerican geologists.

A killer superquake is long overdue in the Pacific Northwest region of the United States and when—not if—it hits it will trigger a massive tsunami that will virtually wipe out many of the cities on the northern West Coast. The tsunami may be so powerful it could even reach as far as eastern Japan, warn scientists.

New data revealed by intensive research undertaken by the Active Tectonics and Seafloor Mapping Laboratory at Oregon State University has raised awareness of the horror that awaits the Northwest when a 9.0 or greater earthquake slams the unprepared population of such cities asVancouver, Seattle and Portland.

Hundreds of thousands could be killed

The potential devastation is so great it seems unreal. The most terrifying Hollywood disaster movies barely begin to scratch the surface of the death destruction and smoldering aftermath of ruins left in the wake of the coming superquake.

Like the Pacific plate thrust that decimated northeastern Japan, the greater portion of the sprawling Pacific seaboard faces a similar catastrophe.

The Pacific Northwest is at the mercy of a huge tectonic plate known as the Juan de Fuca plate. When it is eventually forced beneath the titanic North America plate on the Cascadia fault line Doomsday will have arrived for the peoplealong the northern coast.

Energy released by quakes of that magnitude are literally off the chart. The Japanese mega-thrust quake has been estimated by seismologist David Wald to have released energy about equal to all the energy the United States uses in an entire year.

And it released all that energy in a handful of minutes.

According to the London Times, the cracking Juan de Fuca plate slips about every 240 years generating a megaquake of magnitude eight or higher.

The last superquake along the Cascadia fault occurred more than 300 years ago, so following the average the Pacific Northwest is 60 years overdue for a major to great quake.

The potential disaster zone sweeps downward from VancouverIsland to the northern region of California. Experts worry about the infrastructure as many skyscrapers at at risk, thousands of schools, and thousands of coastal cities.

All could be inundated, swept away by a roaring tsunami pushing a wall of water towering five stories or higher hundreds of miles an hour along the coast.

The surging tidal water would act like a merciless blade scraping the coastal regions clean as far as several miles inland.

Odds increasing

Scientists believe the odds of such an event occurring in the near future have now reached the proverbial 50-50 range.

In essence, that means they just don’t know. But all agree that a mega-thrust quake will hit the region, it’s not a question of if, but when.

“We don’t know how to tell you, ‘Hey, next week, you know, get out of town there’s going to be a big earthquake,’” said Tom Jordan, the director of the Southern California Earthquake Center to the Times.